Mercedes 12.8L consuming motor oil

[willie59]

Anybody familiar with the Mercedes 12.8L? We have one in a 2004 Freightliner that consumes motor oil, probably about a gallon a week. Yes, it's got 510K miles, but it fires right off even cold, no starting fluid needed, runs and pulls strong. It's used mostly to move trailers in and out of our production plant, doesn't work hard doing so. After days of doing that, if you hook up a trailer to make a delivery with it, once you mash the gas to get on the big road it clears out the oil that's accumulated, smoke out of the exhaust and you can smell the oil burning in the exhaust almost like an old 2 stroke Detroit after idling for extended periods. A few miles down the road it's burned out and running clean, no exhaust smoke. Aside from worn out engine, which I find hard to believe as good as it runs, or a failed turbo leaking oil, is there a component on this engine that could ingress motor oil into the combustion chambers or exhaust?

 

[terex herder]

valve guides

 

[willie59]

Ok, hadn't considered that, I suppose that's possible on a turbo engine as turbo pressure would be low at idle or just puttering around.

 

[Nige]

valve guides

And/or valve guide seals if the engine has them.

When it's out on the road and the smoke has cleared try running it on a fairly long downgrade with the throttle pedal released. At the bottom of the grade hit the throttle, if you see a cloud of smoke in your mirrors it's quite likely to be valve guides/seals.

 

[willie59]

And/or valve guide seals if the engine has them.

When it's out on the road and the smoke has cleared try running it on a fairly long downgrade with the throttle pedal released. At the bottom of the grade hit the throttle, if you see a cloud of smoke in your mirrors it's quite likely to be valve guides/seals.

Of course I typically use the engine brake on grades, but that's a good idea, turn the engine brake off and see what the result is after going down a grade.

 

[Truck Shop]

If guides are bad---which I doubt-but, when using the jake on a engine with worn out
cylinder heads and or rings as soon as the jake is flipped on it will emit a cloud of blue
because it's pistons pulling down against a dead cylinder, which will pull oil past guides
and rings till it clears.
*
When following a truck-it's easy to tell the jake is being used because of the puff of blue
each time it comes on.
*
Common on engines used as yard dogs that see no real heat and boost, washed cylinders,
and like said a tired turbo.

 

[willie59]

If guides are bad---which I doubt-but, when using the jake on a engine with worn out
cylinder heads and or rings as soon as the jake is flipped on it will emit a cloud of blue
because it's pistons pulling down against a dead cylinder, which will pull oil past guides
and rings till it clears.
*
When following a truck-it's easy to tell the jake is being used because of the puff of blue
each time it comes on.
*
Common on engines used as yard dogs that see no real heat and boost, washed cylinders,
and like said a tired turbo.

That's the thing, once you get it on the road and get it under boost it clears it out, once you're down the road a few miles it doesn't smoke at all and will pull 40K like a mule with a 10 speed.

 

[Truck Shop]

That's the thing, once you get it on the road and get it under boost it clears it out, once you're down the road a few miles it doesn't smoke at all and will pull 40K like a mule with a 10 speed.

IMO--if it was run steady for 30 days may see it clean up/or use less oil. If it has no lack of
power and smoke stops---------.

 

[willie59]

IMO--if it was run steady for 30 days may see it clean up/or use less oil. If it has no lack of
power and smoke stops---------.

Yeah, that ain't gonna happen, it's a yard dog, except for the few times the newer Pete is out of town or when the newer Pete is hospital with the "check engine" light on

 

[Truck Shop]

it's a yard dog,

That's the answer to the issue. Worst engine I have ever seen used for a yard dog was a 3208
for oil consumption and smoke.

 

[willie59]

That's the answer to the issue. Worst engine I have ever seen used for a yard dog was a 3208
for oil consumption and smoke.

Naa, that would be a Detroit, Cat 3208 was born to smoke no matter what you used them for.

 

[Birken Vogt]

3208s ran fine and clean if kept at high RPM and worked hard on the road, not hard to do with the low power, but if left to idle for 20 minutes or an hour would lay down a log of bluish white smoke like nothing else.

I could only imagine what slobber a yard dog would be like.

 

[Truck Shop]

Some agreement--Detroit and cat 3208 are both piles.

 

[cfherrman]

Always high idle the truck and take it up a hill loaded as much as you can. Make plans to buy a yard truck that's powered by something like a 12v Cummins so you stop damaging that truck.

 

[bccat]

I have seen lots of 3208’s in Marine applications,( not boat anchors )mostly pleasure boats, worked on them once in awhile, mostly just serviced & tune ups, they were popular with the Owner’s. Pretty Reliable, But the environment has a lot to do with it, a 3208 TA would get up and go, l liked them, mostly they were nice and quiet, those jimmies especially the 6 v53 series were fricken loud especially in a steel hull, no wonder I have Tinnitus . The 149 series were bad

 

[Volvomad]

Seen ag tractors like that. Nothing usually wrong with them that hard work didnt fix

 

[Birken Vogt]

Yes the 3208s were just a soft whisper compared to a Jimmy. One of the reasons I kind of liked them.

 

[farmerlund]

My guess is the oil rings are shot/ gummed up or something of that nature. When you idle around with no boost the oil sneaks up to the piston top. Under boost the positive air pressure keeps it down where it belongs. Could posibly apply to the guides as well, but I'm not a professional. LOL